Door closer

Abstract: A door closer (20) is attachable to a door (24) and includes a cylinder (36) which forms a chamber (44) in which a piston element (50) is movable to move fluid from the chamber to a reservoir (82) upon opening of the door. After the door (24) has been opened to a position, for example, of ninety-five to one hundred degrees, continued opening of the door causes the fluid to be compressed within the chamber (44) and to be directed only through a back check valve (95) to the reservoir (82). This results in the development of an adjustable "back check" condition to provide a counterforce to the continued opening of the door, A passageway (150) is formed in cylinder (36) to allow fluid to flow relatively freely from chamber (44) to reservoir (82) until an inward end (56) of piston element (50) has travelled a prescribed distance "x". This prescribed distance of travel represents the opening of door (24) to ninety-five to one hundred degrees from the door's normally closed position.

Description: This invention relates to a door closer, in particular to a door closer which allows the associated door to swing to a relatively wide opening with relative ease before opposition to further opening of the door is increased. Door closers are typically formed by a cylinder which is coupled to a spring tube to form an enclosed main chamber containing fluid (e.g. oil) within the cylinder and tube. A piston is located within the cylinder for movement within the chamber. At least one coil spring is located within the tube portion of the chamber and is in axial engagement with one end of the piston, normally to urge the piston into the cylinder portion of the chamber when the associated door is closed. An elongated opening is formed through the piston and extends from near one end of the piston to near the other end thereof. One side wall of the elongated opening is formed with teeth to form a rack. A pinion is located within the elongated opening so that the teeth of the pinion mesh with the teeth of the rack. Driving elements are formed on opposite sides of the pinion and extend through the sidewall of the cylinder to allow coupling of the driving elements and the pinion to facilities external of the cylinder. A door closer of this type can be mounted on one surface of a door near the top where one of the driving elements is coupled to one end of a first linkage arm. The other end of the first arm is coupled to one end of a second linkage arm for hinged movement relative thereto while the other end of the second arm is coupled for pivotal movement to a bracket which is fixedly secured to the door frame. When the door is in the closed position, the linkage arms are positioned so that the spring is urging the piston into the end of the cylinder portion of the chamber which is furthest from the spring tube. As the door is opened, the linkage arms are moved so that the first arm causes the driving element and pinion to rotate about the axis of the pinion. As the pinion rotates, the mesh of the pinion and rack teeth cause the piston to move against the biasing action of the spring and toward the tube portion of the chamber. A reserve chamber or reservoir is formed in the cylinder and communicates with the main chamber through a main passageway and a back-check passageway of restricted opening formed in the cylinder wall. As the piston is moved upon opening of the door, some of the fluid is initially urged from the main chamber through the main passageway and the back-check passageway of restricted opening and into the reservoir. Eventually, the piston is moved sufficiently to cover the main passageway whereby the fluid now travels only through the back-check passageway into the reservoir. This condition occurs, for example, when the door is opened about sixty-five to seventy degrees from a closed position. The fluid now begins to be compressed within the main chamber with the only outlet being through the back-check passageway and thereby provides a "back check" condition to prevent the door from being swung open too swiftly. A door closer of the type described above is described and claimed in US Patent No. 5,259,090. GB-A-1576292 discloses a door closer comprising a movable unit for forcing pressure fluid through a flow duct in dependence on the movement of a door adapted to be attached to said movable unit, and flow restricting means positioned within the flow duct for influencing the speed of the opening movement of a door attached to the movable unit and comprising valve means, fluid flow control means having a passage for the flow of fluid therethrough, the fluid flow control means defining with the flow duct a throttled flow duct and being moveable within the flow duct between a first portion preventing or restricting the flow of fluid through said throttled duct and a second position enabling, or allowing less restricted, fluid flow through said throttled duct, the valve means and the fluid flow control means being movable relative to each other into and out of a closed position in which fluid flow through said passage is prevented or substantially restricted, first spring means acting to urge the fluid flow control means and the valve means out of the said closed position, and second spring means acting to resist movement of the fluid flow control means into the said second position, whereby flow pressure, caused by movement of the moveable unit, is adapted to act on the flow restricting means to move the fluid flow control means and valve means relatively to each other into said closed position, whereafter, with the fluid flow control means and valve means in said closed position and on increasing flow pressure acting on the flow restricting means, said fluid flow control means is adapted to be moved within the flow duct out of said first position and, against the force exerted by said second spring means, into said second position. Due to certain conditions involving use of the door with the door closer, one may wish to be able to open the door more freely by a greater amount before the back-check condition is effected. For example, it may be desirable to open the door with relative ease to a position greater than ninety degrees from the closed position to allow those passing through the door portal to move without the increased opposition to opening of the door which is encountered when the back-check condition is effected. Thus, there is a need for a door closing having facility for allowing the related door to be opened with relative ease to a position greater than ninety degrees and prior to any increased opposition to the opening of the door by the occurrence of the back-check condition. It is, therefore, an object of the present invention to provide a door closer which allows free opening of a related door to a relatively wide position before occurrence of opposition to door opening by the back-check condition. Another object of this invention is to provide a door closer which allows a related door to be opened essentially freely to a position at least ninety degrees from the closed position whereafter opposition to further door opening is increased through a back-check valve. The present invention provides a door closer for connecting to and controlling the selective application of a counterforce to the opening of a door, which comprises: a housing; a chamber formed within the housing for containing a fluid therein, the chamber being formed with a first portion and a second portion; a piston element located in a normal position in the first portion thereof when the door is closed, and movable within, the chamber; the piston element formed with a forward face; means responsive to forces externally of the chamber for moving the piston element toward the second portion of the chamber to initiate compression of the fluid therein; at least a first passageway formed in said housing and extending a preselected distance from the forward face of the piston element when the piston element is in the normal position; said preselected distance being representative of the door beings opened less than ninety degrees from a door position when the door is closed; and being characterised by at least a second passageway formed in the housing a prescribed distance from the forward face of the piston element when the piston element is in the normal position; the prescribed distance being representative of the door being opened at least ninety degrees from a door position when the door is closed; the first and second passageways being in communication with the chamber to allow at least portions of the compressing fluid to be forced out of the chamber and through the passageways upon movement of the piston element within the chamber from its position normally in the first portion of the chamber and until the forward face is respectively moved past the first and second passageways; and means for developing a counterforce to the continued opening of the door after the forward face has been moved past the second passageway. An embodiment of a door closer according to the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a partial front view showing a door closer in assembly with a door and related door frame; Figure 2 is a top view of the door closer of Figure 1 showing the door in a closed position and in an open position of less than ninety degrees from the closed position; Figure 3 is a top view of the door closer of Figure 1 showing the door in the closed position and in an open position of more than ninety degrees from the closed position; Figure 4 is a side view showing the door closer of Figure 1 in assembly with the door and related door frame; Figure 5 is a sectional view of a door closer embodying certain principles of the invention; Figure 6 is an enlarged sectional view of a portion of the door closer of Figure 5 further showing features embodying certain principles of the invention; and Figure 7 is a partial sectional view showing a valve arrangement in the door closer of Figure 1 for adjusting a passageway opening through which pressurised fluid will flow. Referring to Figures 1, 2 and 3, a door closer (20) is enclosed within a cover (22) and is typically mounted to the upper surface of a door (24) such as a heavy duty door. One end of a first actuator arm (26) is coupled for pivoting movement to a door closer (20) and is connected for pivoting movement to a second actuator arm (28). The other end of arm (28) is connected for pivoting movement to a bracket (30) which is mounted on a door frame (32) associated with door (24). Referring to Figure 2, as door (24) is opened or closed, arm (28) is pivoted with respect to bracket (30) and results in pivoting movement of arm (26) which is coupled to door closer (20). As door (24) is opened, a mechanism within door closer (20) is operated to provide opposition to the rapid opening of the door and eventually to provide a back pressure when the door reaches, for example, an opening of sixty-five to seventy degrees which is represented in phantom in Figure 2. It then becomes increasingly more difficult to open the door to a full open position. In effect, then, door closer (20) provides a back pressure as the door is opened to these positions to establish a "back check" condition as if there was a physical impediment in the path of the door which must be overcome to open the door further. This feature is useful, for example, where heavy doors are used and where the rapid opening of such doors could result in serious injury to anyone near the opening side of the door or could result in serious and costly damage to the door and surrounding structure. Door closers of this type have been used in the past and are described and claimed in U.S. Patent No. 5,259,090. As shown in Figure 4, a door closer according to the invention includes provision for opening the door (24) from a closed position to an open position of at least ninety degrees from the closed position, and preferably in a range of ninety-five to one hundred degrees, before application of the opposition to opening of the door as provided by the back pressure. The illustration of Figure 4 represents a door opening in the preferable range of ninety-five to one hundred degrees from the closed position of door (24). As shown in Figure 5, one of the preferred embodiments of the invention includes the door closer (20) with a housing (34) formed by a cylinder (36) and a spring tube (38) threadedly joined together. Cylinder (36) and spring tube (38) are assembled together in axial alignment so that a cylinder opening (40) and a tube opening (42), respectively, join to form a chamber (44). A first cap (46) is located over one end of cylinder (36) and a second cap (48) is located over one end of spring tube (38) to enclose chamber (44) between the caps. A piston element (50) is normally located in a first portion of chamber (44) generally defined by about two-thirds of opening (40) of cylinder (36). A pair of compression springs (52) and (54) are captured within chamber (44) between an inward end (56) of the piston element (50) and the tube cap (48). Springs (52) and (54) are located in a second portion of chamber (44) defined by the remaining one-third of cylinder opening (40) and all of tube opening (42). Further, the second portion of chamber (44) which includes springs (52) and (54) is typically filled with a fluid such as, for example, oil which is not readily compressible. Piston element (50) is formed with an elongated opening (58) which is enclosed at the axial ends thereof but is open from side to side. An elongated wall (60) of opening (58) is formed with teeth (62) which extend inwardly of the opening to form a rack (64). A driving pinion (66) having teeth (68) about the periphery thereof is located within opening (58) at one end thereof as illustrated in Figure 5, with the teeth of the pinion being in mesh engagement with the teeth (62) of rack (64). A pair of coupling elements (not shown) which are capped by square heads (74) and (76) (Figure 4), respectively, are formed integrally with pinion (64) and extend axially from opposite sides thereof to locations externally of cylinder (36). Referring to Figure 4, a hub end (78) of arm (26) is located over square head (74) for driving connection therewith. In this arrangement, square head (76), which is not used, is covered by protective cap (80). Referring again to Figure 5, a reservoir (82) is formed at the side and extends from the top to the bottom of cylinder (36) and communicates with chamber (44) through an opening (84). Further, a bevelled slot (86) is formed in cylinder (36) to provide another path of communication between chamber (44) and reservoir (82) through opening (84). As viewed in Figures 5 and 6, a passageway (88) is formed in cylinder (36) for providing another path of communication between chamber (44) and reservoir (82) and includes a flow passage (90), a valve chamber (92), and a flow passage (94). A valve (95) embodying certain principles of the invention is threadedly located within valve chamber (92) the axis of which is parallel to the longitudinal axis of cylinder (36). Referring again to Figure 5, other flow passages (96), (98) and (100) are formed in conjunction with a valve chamber (102) to provide still another communication passageway between chamber (44) and reservoir (82). A threaded valve (104) is located in valve chamber (102) and is formed with a slotted head (106) at one end and a tapered portion (108) at the other end. Valve (104) can be adjusted threadedly within the chamber (102) to position the valve and the tapered portion (108) thereof to control the flow rate of the fluid through passages (98) and (100), valve chamber (102), passage (96) and into reservoir (82). A valving arrangement such as that which includes valve (104) is used to control the allowable speed of door closing at the time of latching. Referring now to Figures 5 and 6, back check valve (95) includes a threaded portion (120) at one end (122) thereof which is threadedly positionable within a threaded portion (124) of valve chamber (92). Another end (126) of valve (95) is formed with a slide portion (128) and an external head (130) with a slot (132) to facilitate threaded mounting of the vale within chamber (92). Slide portion (128) is formed with an annular groove (134) and receives a pliable "0" ring (136). Back check valve (95) is also formed with a transverse passage (138), axial passage (140) and chamber (142). Passage (138) is in communication with passage (140) which, in turn, is in communication with chamber (142). A spherical member or ball (144) is positioned within chamber (142) adjacent to port (140a) associated with passage (140) and is normally held in this position by a compression spring (146) after valve (95) has been threadedly seated in chamber (92) as illustrated in Figures 5 and 6. Literally, then, ball (144) closes port (140a) until the ball is urged toward the other end of chamber (92) against the biasing action of spring (146). When valve (95) is used in the manner described in U.S. Patent No. 5,259,090 the valve is threadedly mounted into chamber (92) as illustrated in Figures 5 and 6. In this position, the tail portion of compression spring (146) is resting against end wall (148) of chamber (92) to apply a compressing force against ball (144). This action urges ball (144) into blocking position over port (140a). The compression force applied by spring (146) against ball (144) can be adjusted as desired by the location of valve (95) within chamber (92). This will establish the level of force of the fluid as applied against ball (144) at port (140a) necessary to overcome the force of spring (146) thereby to allow the ball to be moved from the port and fluid to pass through the port. For example, as illustrated in Figures 5 and 6, valve (95) is assembled fully within chamber (92) so that valve end (122) seats against end wall (148) of chamber (92). In this position spring (146) is compressed to the maximum level and thereby applies the maximum force possible to hold ball (144) over port (140a). The force of the fluid being compressed in chamber (44) must exceed the level of force applied to ball (144) by spring (146) to cause the ball to be moved from port (140a). If valve (95) is adjusted so that valve end (122) is not in engagement with chamber wall (148), spring (146) expands and is relaxed in comparison to the maximum available compression described above. In the relaxed condition, the force applied by spring (146) against ball (144) is less than the maximum force noted above. Thus, the force of the fluid against ball (144) required to overcome the force applied by relaxed spring (146) is less than the force of the fluid noted above when the spring was in the maximum force condition. With this flexibility, the arrangement of ball (144) and spring (146) with valve (95) permits adjustment of the valve to many selectable positions to develop the desired level of force which the compressing fluid must present in the establishment of the "back-check" condition. When valve (95) is mounted within chamber (92) as illustrated in Figures 5 and 6, transverse passage (138) of the valve is in communication with passage (90) of cylinder (36) while chamber (142) of the valve is aligned and in communication with passage (94) of the cylinder. As piston element (50) is moved to the right (Figure 5) upon the opening of door (24), fluid is moved through passage (90), into passage (138) and further into passage (140). The force of the fluid upon ball (144) will attempt to move the ball against the biasing action of spring (146). Also, "O" ring (136) forms a seal against the wall of chamber (92) to preclude any fluid from leaking toward the open end of the chamber adjacent head (130). If piston element (50) has not been moved past opening (84) and slot (86), door (24) is being opened with only moderate opposition offered mainly by springs (52 and 54). In this mode, the force of the fluid against ball (144) is not sufficient to move the ball slightly away from port (140a) to allow fluid to flow into chamber (142) and eventually through passage (94) into reservoir (82). Again, since piston element (50) has not been moved past opening (84) and slot (86), door (24) continues to be moved with only moderate opposition. Therefore, valve (95) plays no role in offering opposition to the opening of door (24) at this time. Eventually, door (24) is opened to a position between sixty-five and seventy degrees, for example, as illustrated in Figure 3 whereby opening (84) and slot (86) are covered by piston element (50) in the manner described above. At this time, any fluid which will flow into reservoir (82) must pass through passages (90, 138 and 140), chamber (142) and passage (94). In order for fluid to pass from passage (140) into chamber (142), the force and pressure of the fluid being compressed by movement of piston element (50) to the right (Figure 5) must move ball (144) away from port (140a). The level of force of the fluid as applied against ball (144) moves the ball against the biasing action of spring (146) and thereby overcomes, partially, the compressing force of the spring. As ball (144) is moved away from port (140a), fluid is then allowed to be moved from passage (140) into chamber (142) and eventually into reservoir (82). Thus valve (95) is directly responsive to the compressing force being developed by the compression of fluid within chamber (44) upon movement of piston element (50) into the chamber. If door (24) is being opened in a normal manner with moderate force, piston element (50) will move at a pace which allows some of the fluid to move through opening (84) and slot (86) into reservoir (82). Thereafter, the continued application of a moderate force in opening door (24) results in compressing of the fluid within chamber (44). This causes a moderate compression force to be applied against ball (144) to move the ball as noted above a distance away from port (140a) determined by the instantaneous compression force and the biasing force of compression spring (146). In any event, the opening provided by the space between ball (144) and port (140a) is sufficient to allow fluid to flow through valve (95) at a rate commensurate with the level of compression force within chamber (44) required to establish the "back check" condition. In the event that door (24) is opened in a violent manner, piston element (50) quickly passes by opening (84) and slot (86) and begins to compress the fluid within chamber (44). As the compression force builds rapidly, a force is applied against ball (144) to move the ball from port (140a) The compression force developed under the violent-opening condition is much higher than the compression force of the normal opening as described above. In the instance of the violent opening, the force upon ball (144) is significantly greater than the normal-opening force and the ball is moved a greater distance from port (140a) and thereby allows a higher rate of fluid through valve (95). Thus, even though the fluid is being compressed at an extremely rapid rate within chamber (44), the permissible high rate of flow through valve (95) prevents the development of destructive compression forces within the chamber and allows the establishment of the "back check" condition. Thus, the structure of valve (95) responds to the force of opening door (24), regardless of whether the door is opened in a normal manner with moderate force or in a violent manner with exceptional force, and allows for the development of sufficient counterforce to establish the "back check" condition. In one embodiment of the invention as illustrated in Figure 5, a passageway (150) is formed in the cylinder (36) which is located between the bevelled slot (86) and the passageway (90) but is not directly linked thereto. The passageway (150) communicates with the chamber (44) at one end thereof and with a chamber (152) at the other end thereof. Further, the passage (94) also communicates with the chamber (152). The passageway (150) is located by a prescribed distance "x" from the inward end (56) of the piston element (50) when the element is in a normal or rest position to the left in the chamber (44) as shown in Figure 5. It is noted that the inward end (56) of the piston element (50) represents a forward face of the piston element with respect to the direction of movement of the element when the door (24) is opened. When the door (24) is opened, the piston element (50) moves to the right as described above whereby fluid flows through the opening (84) and the slot (86) into the reservoir (82). Some fluid will also flow through the passageway (150) and eventually into the reservoir (82). However, the compression of the fluid at this stage is insufficient to move the ball (144) so that fluid does not flow through the back check valve (95) at this time. Eventually, the inward end (56) of the piston element (50) is moved past the opening (84) and slot (86) and the fluid now passes only through the passageway (150) into the reservoir (82). Even so, the door (24) continues to open with relative ease because the passageway (150) is of sufficient diameter to allow for the flow of the fluid therethrough without significant counterforce to the opening of the door. When the inward end (56) of the piston element (50) has travelled distance "X", the door (24) has now been opened at least ninety degrees and preferably with ninety-five to one hundred degrees from the closed position as illustrated in Figure 3. At this time, the passageway (150) is blocked by the piston element (50) and the fluid becomes more compressed within the tube opening (42). This results in the compressed fluid attempting to and eventually flowing through the valve (95) which establishes the back check condition, and the counterforce associated therewith, in the manner described above. Thus, the placement of the passageway (150) by the prescribed distance "X" from the inward end (56) when the piston element is in the normal rest position provides the facility for allowing the door (24) to be opened freely and with relative ease to at least ninety degrees, and preferably from ninety-five to one hundred degrees, from the closed position before application of the back check counterforce. In an alternative embodiment as illustrated in Figure 6, a passageway (150a) is formed at an angle in the cylinder (36) instead of the passageway (150). The passageway (150a) is situated in the same general location as the passageway (150) and also communicates with the chamber (44) and the chamber (152) at opposite ends of the passageway (150a). The passageway (150a) is located at a prescribed distance "X" from the inward end (56) of the piston element (50) and functions as described above with respect to the passageway (150). Referring to Figure 7, a valve (154) with a forward section (156) is threadedly mounted in the cylinder (36). The valve (154) is positioned so that, upon threaded adjustment of the valve, the forward section (156) will restrict the opening between the passageway (150), or passageway (150a), and the chamber (152) and thereby control the rate of flow of fluid through the passageway. Thus, the valve (154) provides the ability to introduce a moderate counterforce to the opening of the door (24) after the inward end (56) has been moved past the slot (86). Also, the valve (154) can be adjusted to block the passageway (150), or passageway (150a), so that the door closer (22) now functions in the manner described above with respect to the door closer in U.S. Patent No. 5,259,090.

Claims: A door closer (20) for connecting to and controlling the selective application of a counterforce to the opening of a door, which comprises: a housing (34); a chamber (44) formed within the housing for containing a fluid therein, the chamber being formed with a first portion and a second portion; a piston element (50) located in a normal position in the first portion thereof when the door (24) is closed, and movable within, the chamber (44); the piston element (50) formed with a forward face (56); means responsive to forces externally of the chamber for moving the piston element (50) toward the second portion of the chamber (44) to initiate compression of the fluid therein; at least a first passageway (84, 86) formed in said housing (34) and extending a preselected distance from the forward face (56) of the piston element when the piston element (50) is in the normal position; said preselected distance being representative of the door beings opened less than ninety degrees from a door position when the door is closed; and being characterised by at least a second passageway (150) formed in the housing a prescribed distance from the forward face (56) of the piston element when the piston element (50) is in the normal position; the prescribed distance being representative of the door being opened at least ninety degrees from a door position when the door is closed; the first and second passageways (84, 86; 150) being in communication with the chamber to allow at least portions of the compressing fluid to be forced out of the chamber and through the passageways upon movement of the piston element within the chamber from its position normally in the first portion of the chamber and until the forward face is respectively moved past the first and second passageways; and means for developing a counterforce to the continued opening of the door after the forward face has been moved past the second passageway. The door closer as set forth in claim 1, wherein the prescribed distance is representative of the door being opened within a range of ninety-five to one hundred degrees. The door closer as set forth in claim 1, wherein the second passageway extends perpendicularly from the chamber. The door closer as set forth in claim 1, wherein the second passageway extends angularly from the chamber.

Inventors: FAYNGERSH ZAKHARY, FAYNGERSH, ZAKHARY
Applicants: CORBIN RUSSWIN INC, CORBIN RUSSWIN, INC.
Application year: 1994
Main classification: E05F3
IPC codes: E05F3